The market reacted negatively to news of the United Kingdom's referendum vote to withdraw from the European Union, a decision nicknamed "Brexit," and the announcement that British Prime Minister David Cameron plans to resign, USAToday reported.

Some Hanover-Adams residents took to social media Friday to express concerns over the news' impact on their stock investments for retirement.

Evans, who works for Benchmark Investments & Insurance and has more than 30 years of experience, believes the market behavior is, to put it simply, a fluctuation, she said.

"This is a temper tantrum by the markets that was fully expected," Evans said. "People should look at the long term. You always have short term fluctuations in the market. Keep your eye on the long term."

People who rely on 401(k) accounts for retirement should remember that they are only withdrawing small percentages of their investments at a time. Those accounts will have plenty of time to recover following economic upset, she said.

"I know people emotionally go look at their account and say, 'Oh, my account is down; I can't retire,'" Evans said. "It's not like you're pulling it all out today. The rest of the account has a chance to rebound."

According to a USAToday report, the Dow Jones industrial average tumbled 515 points in midday trading Friday, a 2.9 percent drop. The S&P 500 was off 3 percent, while the Nasdaq composite was down 3.7 percent.

From a historical point of view, market reactions like this happen from time to time, said financial advisor Rob Miller, of Riggle & Associates Wealth Management and Cetera Advisor Networks, LLC., in Hanover.

Investors and financial advisors use certain terms to gauge these market reactions, calling them "bear" or "bull" markets depending on how far they swing in one direction, Miller said.

Bear markets describe when a decline is greater than 20 percent, and bull markets describe a market upswing. The last bear market occurred between 2007 and 2009, he said.

Another term, "correction," describes when the market drops by more than 10 percent, Miller said. Right now, the market has not dropped far enough to earn the description of a "correction," he said.

"There's always risk in the market," Miller said. "Days like this do happen. That's why retirement income planning is key. A lot of clients we have that have that planning in place, they are less worried about days like this."

In general, determining the best way to manage investments is really down to an individual's life circumstances, Miller said.

Still, some experts say investors should be wary of the market fluctuations. Ryan Fox, a Gettysburg-based financial advisor with Huston Fox Financial Advisory, believes investors should be "concerned, but not worried," he said.

Fox himself was awake late into the night watching the British vote counts roll in, he said.

"Concerned means keeping an eye on the volatility," Fox said. "This was a large economic event. The global stock markets will rebound, though, once the information is digested. It will be several years at least for the U.K. to negotiate terms of departure."

The global and U.S. market reactions were, in part, because major Wall Street firms did not anticipate that the majority of British people would vote in favor of leaving the E.U, Fox said.

"It was like pulling the rug out from everyone, and underneath it was icy and everyone fell flat on their face," he said, adding that markets tend to have knee-jerk reactions to news like this.